2015-03-03T20:33:18ZElectrical impedance measurements on electropermeabilized cells attached to microelectrodeshttp://hdl.handle.net/2117/26159
Title: Electrical impedance measurements on electropermeabilized cells attached to microelectrodes
Authors: García Sánchez, Tomás; Sánchez Terrones, Benjamin; Gomez Foix, Anna Maria; Bragós Bardia, Ramon
Abstract: The aim of this study is to use fast electrical impedance spectroscopy to measure the process of electroporation applied on cell monolayers growing attached to a specifically designed set of microelectrodes. The frequency response of the impedance can provide useful information about the extent of permeabilization in the cell membranes exposed to high electric fields and also the time dynamics of creation and resealing of the ”‘pores”’ created. Cell line CHO-K1 was cultured as a monolayer on a microelectrode assembly fabricated on Indium Tin Oxide substrates. Additionally, propidium iodide fluorescent dye was used to asses the success of permeabilization of cells. Results show two different resealing dynamics corresponding with the presence of two different type of pores (short-lived VS long-lived pores) and how information at different frequencies is valuable to separate different effects namely pore dynamics and release of intracellular contents.2015-01-29T12:26:33ZEvolución dinámica de la membrana celular durante la electroporación: Medidas de espectroscopia de impedancia eléctricahttp://hdl.handle.net/2117/25785
Title: Evolución dinámica de la membrana celular durante la electroporación: Medidas de espectroscopia de impedancia eléctrica
Authors: García Sánchez, Tomás; Gomez Foix, Anna Maria; Rosell Ferrer, Francisco Javier; Bragós Bardia, Ramon
Abstract: Las medidas de las propiedades eléctricas de los tejidos biológicos son un instrumento interesante para la
caracterización de procesos celulares. En el presente estudio se muestra como las medidas de espectroscopia de impedancia
eléctrica son una herramienta útil para el estudio de los cambios dinámicos producidos en la membrana celular durante
el proceso de electroporación. Aplicando técnicas rápidas de medida de impedancia basadas en señales multiseno, este
estudio, realizado durante la electroporación de células adherentes creciendo sobre microelectrodos, muestra dos comportamientos dinámicos diferentes en la membrana celular.
También se pone de manifiesto cómo las medidas multifrecuencia son útiles para la extracción de información sobre diferentes procesos que tienen lugar durante la electropermeabilización.
Adicionalmente se utiliza las medidas de
impedancia también para monitorizar el estado del cultivo antes y después del tratamiento de electroporación.2015-01-15T19:07:17ZLocalized BIA in muscle injurieshttp://hdl.handle.net/2117/25144
Title: Localized BIA in muscle injuries
Authors: Yanguas Leyes, Javier; Nescolarde Selva, Lexa Digna; Alomar, Xavier; Lukaski, Henry; Rodas Font, Gil2015-01-03T15:55:44ZUse of reference limits in the Feature Selective Validation (FSV) methodhttp://hdl.handle.net/2117/24758
Title: Use of reference limits in the Feature Selective Validation (FSV) method
Authors: Jauregui Telleria, Ricardo Ignacio; Pous Solà, Marc; Silva Martínez, Fernando
Abstract: This paper presents a method for taking into account reference limits when the Feature Selective method (FSV) is applied. Nowadays, there is a long line of research that underlines the important role played by the FSV to perform an objective validation process. However, until now, there has been no consideration of a reference level in the validation process. This paper presents a methodology to calculate the FSV values when a reference limit is contemplated. We demonstrate the importance of this technique in the validation criteria for the Computational Electromagnetics and, more particularly, in the EMC comparison process. Finally, in order to show the application and the importance of the method, two real cases, considering different reference levels, are analysed.2014-11-19T14:17:47ZAPD radiated transient measurements produced by electric sparks employing time-domain captureshttp://hdl.handle.net/2117/24757
Title: APD radiated transient measurements produced by electric sparks employing time-domain captures
Authors: Pous Solà, Marc; Silva Martínez, Fernando
Abstract: Electric sparks phenomena produce electromagnetic radiated transient noise which is one of the main interference causes that disturb digital communication systems such as DVB-T or GSM-R. Detectors and methodologies defined at the EMC harmonized standards are not sufficient to measure and characterize properly this type of interference noise. Otherwise, amplitude probability distribution (APD) detector is an appropriate measurement to reach the main parameters of impulsive interferences; as in addition to acquire the amplitude of the disturbance, it provides statistical information. Moreover, the APD diagram of an interference has been related to the bit error probability of some digital coherent radio receivers. In this paper, an ESD spark generator according to EN 61000-4-2 has been employed to produce radiated transient interferences to evaluate the impact over the APD results considering several frequency bands. Several APD measurements have been carried out employing an EMI receiver and also an oscilloscope for validation propose. The radiated transient produced by the sparks has been evaluated at GSM-R and TETRA frequency bands. Results shows that GSM-R system can be interfered by ESD electric sparks and emphasize the powerful capabilities of the time-domain procedure.2014-11-19T13:54:30ZTime-domain electromagnetic interference measurement system for intermittent disturbanceshttp://hdl.handle.net/2117/24756
Title: Time-domain electromagnetic interference measurement system for intermittent disturbances
Authors: Costa Godo, Gerard; Pous Solà, Marc; Atienza Picola, Andreu; Silva Martínez, Fernando
Abstract: In Electromagnetic Compatibility emission measurements, a common problem takes place when equipment producing intermittent disturbances are measured according to standard procedures. In many cases, it is impossible to capture the maximum emission using conventional receivers with only one or several sweeps. A significant measurement improvement is possible when time-domain captures and post-processing implementing digital fast Fourier transform (DFT) is used to obtain the frequency spectrum. In addition, the time-domain method offers the possibility to capture all the spectrum frequency range of one single event and evaluate rapidly all the different functional modes of a complex EUT. In this paper, the time-domain method is described and validated for conducted emissions test. For the validation proposes, a multisine signal is measured using the developed method and the results are compared with results acquire from an EMI receiver. Finally, after validation, the time-domain method is applied to complex equipment observing the main advantages that the developed method provides.2014-11-19T13:42:54ZLevel of hamstrings damage depending on force-generating capacity and creatine kinase activityhttp://hdl.handle.net/2117/24510
Title: Level of hamstrings damage depending on force-generating capacity and creatine kinase activity
Authors: Carmona, Gerard; Alomar, Xavier; Mendiguchia, Jurdan; Serrano, David; Padullés, Josep Maria; Nescolarde Selva, Lexa Digna; Rodas Font, Gil; Cusso Calabuig, Roser; Guerrero, M.; Idoate, F.; Balius, Ramon; Cadefau, Joan
Abstract: The aim of the present study was to categorize the eccentric exercise-induced
hamstrings damage by using easy measurable markers such as force-generating
capacity and serum
creatine
kinase activity2014-10-30T11:10:49ZCharacterization of acute effects of eccentric exercises on hamstring muscles by MR techniques, localized bioimpedance and creatine kinase.http://hdl.handle.net/2117/24177
Title: Characterization of acute effects of eccentric exercises on hamstring muscles by MR techniques, localized bioimpedance and creatine kinase.
Authors: Alomar, Xavier; Balius, Ramon; Cadefau, Joan; Carmona, Gerard; Cusso Calabuig, Roser; Nescolarde Selva, Lexa Digna; Padullés, Josep Maria; Padullés, Xavier; Rodas Font, Gil; Serrano, D.; Yanguas Leyes, Javier2014-09-26T12:03:11ZLocalized BIA identifies structural and pathophysiological changes in soft tissue after post-traumatic injuries in soccerhttp://hdl.handle.net/2117/24176
Title: Localized BIA identifies structural and pathophysiological changes in soft tissue after post-traumatic injuries in soccer
Authors: Nescolarde Selva, Lexa Digna; Yanguas Leyes, Javier; Lukaski, Henry; Rodas Font, Gil; Rosell Ferrer, Francisco Javier
Abstract: Localized bioimpedance (BIA) was
measured with a single frequency phase-sensitive
analyzer at 50 kHz in three post-traumatic types of
injuries on four professional soccer players: (1) myositis
ossificans, (2) intramuscular seroma and (3) trochanteric
(hip) bursitis. Normal reference value (no injury) was
obtained from the contra lateral not injured limb at a
mirror-like location of the injury. The relative variations
resistance (R) and reactance (Xc) at the time of injury
was confronted with the not injured values. Relative
variations between acute measurements and post
medication ones on intramuscular seroma and bursitis
have been computed. In intramuscular seroma and
trochanteric bursitis we have obtained a percent of
change between injury data and after medical
intervention. On myositis ossificans, localized BIA
showed a 7-8 % decrease in Xc whereas the percent of
change of R was negligible (1 %). These percent of
changes are in concordance with histological evidence. In
the case of a presence of seroma or the lower thigh and
trochanteric bursitis, the soft tissue cavity accumulates
fluid. Post-injury localized BIA, relative with respect to
non-injured side, confirmed sizeable soft tissue
destruction evidenced by 50 % decrease of Xc and 24-31
% decrease of R due to interstitial fluid accumulation.
Once the seroma and the blood in the bursitis was
removed the localized the immediate post-injury BIA
parameters increased as follows: a) intramuscular
seroma + 10 % on R and + 74 % of Xc; b) trochanteric
bursitis + 20 % of R and +24 % of Xc. Localized BIA
other than classifying soft tissue injuries, can be useful to
understand the pathophysiology and structural
impairments of other kind of injuries and to understand
their behavior.2014-09-26T11:19:56ZA comparison of heartbeat detectors for the seismocardiogramhttp://hdl.handle.net/2117/22525
Title: A comparison of heartbeat detectors for the seismocardiogram
Authors: García González, Miguel Ángel; Argelagós Palou, Ariadna; Fernández Chimeno, Mireya; Ramos Castro, Juan José
Abstract: The study aimed to study the accuracy in RR time series derived from the seismocardiogram when employing different heartbeat detectors in subjects measured in a quiet environment. The ECG and seismocardiogram of 17 healthy volunteers was recorded at a sampling frequency of 5 kHz using a Biopac acquisition system. The seismocardiogram was acquired using a triaxial accelerometer (LIS344ALH, ST Microelectronics). Four detectors of the heartbeat from the seismocardiogram were employed relying either on the Continuous Wavelet Transform or bandpass filtering. The detectors adapt their parameters to the morphology of the signal by estimating mean heart rate and the bandwidth of the signal associated to the heartbeat. For all detectors, the standard deviation of the error in the obtained RR time series is in mean slightly higher than 2 ms and the percentage of obtained RR time intervals that have an error higher than 30 ms is around 3.5%. The seismocardiogram, when measured in a quiet environment, can be used instead of the ECG to obtain reliable RR time series when using proper heartbeat detectors.2014-04-04T15:31:26ZCo-simulation methodology to evaluate digital communication systems interfered by transientshttp://hdl.handle.net/2117/22491
Title: Co-simulation methodology to evaluate digital communication systems interfered by transients
Authors: Pous Solà, Marc; Silva Martínez, Fernando
Abstract: In this paper a method combining different types of simulation is used to evaluate transient interferences over a digital communication system at its frequency band. The method combines different simulation stages; the first one is an electromagnetic simulation, with FDTD numerical method, which is carried out to establish the level of the interference coupled to the digital communication system; at the second stage, the simulation of the transmitted data at the communication system is performed introducing the EM interference calculated at the first stage. The result of this co-simulation will be a BER and other useful indicators to quantify the degradation produced by the transient interference. To show the effectiveness of the co-simulation method first of all the method is validated comparing the results with other evaluation techniques, measuring a real interference over an RFID system. The RFID system is according to the ISO 14443 type B standard, and the interference generated is a burst according to 61000-4-4. Once the co-simulation method is validated, the co-simulation system is used to quantify and decide if an EMC redesign technique of the previous scenario is efficient enough to avoid degradation at the RFID system produced by the burst transient interference.2014-04-02T12:37:20ZMethod for forming a magnec field of arbitrary shape from an established templatehttp://hdl.handle.net/2117/22472
Title: Method for forming a magnec field of arbitrary shape from an established template
Authors: Torrents Dolz, Josep M.; Juan García, Pablo; Sánchez Moragues, Miguel Ángel
Abstract: A strategy to design a particular form of magnetic field along an axis from a coaxial inductor is described. The procedure is illustrated with the design of a constant magnetic field inside a cubic inductor. It validates the goodness of the method by comparing the results with all possible combinations of inductance within a limited set of solutions. Keywords: Magnetic field, magnetic sensor, Helmholtz coils.2014-04-01T14:53:08ZModeling the non-stationary behaviour of time-varying electrical bioimpedancehttp://hdl.handle.net/2117/22459
Title: Modeling the non-stationary behaviour of time-varying electrical bioimpedance
Authors: Sánchez Terrones, Benjamín; Louarroudi, Ebrahim; Pintelon, Rik; Bragós Bardia, Ramon
Abstract: The electrical bioimpedance (EBI) measurement of varying biological systems Z(¿,t) (e.g. the heart, the lungs,.) by means of electrical impedance spectroscopy (EIS) remains an open challenge today. Briefly stated, the bioimpedance is widely assumed to be time-invariant when it is measured with the frequency sweep EIS approach. Hence, time-varying changes are thus ignored or treated as a noise source. In this work, we attempt to model the time-variant effects and obtain a simple (periodically) time-varying [(P)TV)] electrical circuit model with (P)TV parameters from experimental in vivo EBI data using the model proposed by Fricke- Morse. The aim is then to illustrate that a limited number of harmonic components of the electrical circuit parameters, which corresponds to an integer number of the bio-system periodicity, can be used to have a realistic evolution of the bioimpedance over time as well as in frequency.2014-03-31T15:07:26ZMethod for forming a magnetic field of arbitrary shape from an established templatehttp://hdl.handle.net/2117/22456
Title: Method for forming a magnetic field of arbitrary shape from an established template
Authors: Torrents Dolz, Josep M.; Juan García, Pablo; Sánchez Moragues, Miguel Ángel
Abstract: A strategy to design a particular form of magnetic field along an axis from a coaxial inductor is described. The procedure is illustrated with the design of a constant magnetic field inside a cubic inductor. It validates the goodness of the method by comparing the results with all possible combinations of inductance within a limited set of solutions.2014-03-31T14:35:24ZElectrical impedance spectroscopy cell monitoring in a miniaturized bioreactorhttp://hdl.handle.net/2117/22357
Title: Electrical impedance spectroscopy cell monitoring in a miniaturized bioreactor
Authors: Martinez Teruel, Jesus; García Sánchez, Tomás; Fontova, Andreu; Bragós Bardia, Ramon
Abstract: Electrical impedance spectroscopy measurement of biologic materials provides information about viable cell density as well as cell size and shape homogeneity. Several experimental and even commercial biomass density probes have been developed both for cell suspensions and monolayer cell cultures in the last twenty years. This communication describes the development of a set of electrodes and circuits designed to add viable biomass density measurement capability to a set of single-use miniaturized bioreactors. Two applications: adherent animal cultures and generic cell suspension cultures drive to the need of providing two electrode sets and two measurement systems with different frequency ranges.2014-03-24T15:17:32Z